Cassette seals are used to seal a wheel bearing for a passenger car or for a truck and to protect the rolling body chamber of the wheel bearing against water, dirt and the like entering from the outside.
A cassette seal 1, which is known per se, as illustrated in FIG. 1, includes two rings 3 and 4 having an approximately L-shaped cross section, the axial sections of rings 3 and 4 as well as the radial sections of rings 3 and 4 being aligned approximately in parallel to each other. Rings 3 and 4 form an inner chamber 6. A sealing arrangement 5, whose sealing lips 5a, 5b, 5c extend in the direction of second ring 4 in inner chamber 6, is vulcanized onto first ring 3. A cylindrical encoder 7, which surrounds the free end of axial section 8, is mounted on the axial section of second ring 4. The free end of the radial section of first ring 3 thus forms a gap 9 together with the end of encoder 7 surrounding free end 8 of the axial section of second ring 4. Due to this design, specifically of the outer diameter of encoder 7, a recirculating effect of dirty water is not achieved during the rotation of encoder 7, so that the tightness of the cassette seal is insufficient, due to the geometry of gap 9.
FIG. 2 shows a cassette seal 2, which is also known, encoder 7 having a so-called twin-axis design on the end of the axial section of second ring 4, including two lips 7a, 7b pointing in the direction of the radial section of first ring 3. While this design permits a recirculation of the penetrating dirty water, due to the rotation of encoder 7, it nevertheless requires a larger radial installation space.